Many consumer-goods and commercial-goods or components of these goods may be subjected to deforming forces that can result in the bending, folding, buckling, or other deflection of the good or component. Sheet-like structures like fabrics, nonwovens, plastic films, laminates, and the like are particularly susceptible to deflection. Generally, it is desirable that sheet-like structures exhibit some degree of rigidity but excessive rigidity can be problematic.
A fastening system is an example of a component on a commercial good or a consumer good that may require a sheet-like structure that exhibits both rigid and pliant characteristics. While a variety of fastening systems exist (i.e., adhesive, cohesive, mechanical such as hook and loop), a sheet-like structure exhibiting both rigid and pliant characteristics would be particularly beneficial in forming a tab and slot fastener. The tab and slot fastener comprises a substantially planar tab member and a substantially planar slot member having a slot (i.e., slit, aperture) there through. In operating the fastener, the tab member is passed through the slot of the slot member to engage the fastening device. Once passed through the slot, at least a portion of the tab member overlaps the slot member to prevent the tab member from disengaging from the slot member.
The tab and slot member will desirably exhibit some degree of rigidity. For example, an engaged (i.e., fastened) tab and slot fastener may experience a tensioning force where the tab member is pulled in a first direction and the slot member is pulled in a direction opposite of the first direction. With adequate force, the tab member and/or the slot member may deform which can result in unintentional separation of the fastener. For example, the tensioning force may deform the tab member so that it may be pulled back through the slot of the slot member. This unintentional separation of the fastener may be highly undesirable. For instance, the tab and slot fastener may be used in a consumer good such as a diaper to interconnect a front waist section and a rear waist section of the diaper. A tensioning force may be applied to the fastener when the child bends, stretches, or moves. The tensioning force may deform the tab member allowing for unintentional separation of the fastener, which can result in leakage of body exudates. Furthermore, a degree of rigidity in a tab member and/or a slot member may be beneficial for fastening. Without some rigidity, a wearer is required to push or pull a pliant tab member through a pliant slot member. Some wearers, such as infants or the elderly, may lack the necessary dexterity and hand strength to engage that fastener. Also, if the diaper is to be manufactured in a pre-fastened state (i.e., the tab member is inserted in the slot member during manufacture), a non-rigid tab member and/or slot member can cause significant processing complexity.
While the tab and slot members can be made very rigid to prevent deformation, such rigidity is not without drawbacks. For example, a rigid tab and slot fastener used in a diaper may be very uncomfortable for the wearer. A tab and slot fastener that exhibits a degree of rigidity may also resist deformation when subjected to wear forces exerted by the wearer. If the wearer bends or twists, the fastener may remain rigid and may poke or gouge the wearer. It is desirable that the tab and slot fastener exhibit flexibility in order to accommodate and flex with wearer forces.
Absorbent articles are another consumer good that may require a sheet-like structure that exhibits both rigid and pliant characteristics. Absorbent articles typically comprise an absorbent core or pad. Ideally, in some products, the absorbent core will adopt a U-shape while the article is in wear so exudates are contained in the middle of the core. If the core or pad adopts a planar or an inverted U-shape, exudates are prone to flow away from the core and may leak from the absorbent article. Due to packaging constraints, absorbent articles are packaged flat. This prevents the core from being rigidly formed in a U-shape. It would be desirable for the core to comprise a sheet-like structure that will allow the core to adopt a U-shape while in wear while prohibiting the core from becoming inverted (e.g., adopting an inverted U-shape). However, in certain products such as sanitary napkins, it maybe desirable for the core to assume an inverted U-shape. In such an embodiment, it is more preferred to have the core in contact with the wearer.
Furthermore, absorbent articles comprise several gasketing regions, which are areas adjacent to an opening in the article such as a waist opening or a leg opening. The gasketing regions serve to impede exudate leakage from the article. Waist bands, leg cuffs, and other structures within the gasketing regions of the article need to maintain particular orientations to provide maximum gasketing benefit. For example, a leg cuff should ideally fold, bend, or curve inward toward the leg of the wearer in order to provide a tight seal between the cuff and the wearer's leg. In current absorbent article design, the leg cuff is maintained snug against the wearer's leg by using an elastic member under tension. While elastic members typically maintain the cuff in the correct orientation, problems can still occur. For instance, if the cuff is inadvertently inverted during application, the tensioned elastic members may maintain the inverted configuration of the cuff. It would be desirable for the gasketing regions of an absorbent article to comprise a sheet-like structure that may allow for bending or curvature in one direction but will inhibit or prevent bending or curvature in an opposing direction.
In light of the problems highlighted above, it would be advantageous to provide a structure that exhibits less resistance to bend in one direction compared to the resistance to bend in a second direction (which is opposite to the first direction). A structure is needed that deflects a first distance in response to a first force and deflects a second distance in response to a second force, which is of approximately equal magnitude but opposite in direction to the first force, wherein the first distance is greater than the second distance. Such a structure may be useful in a variety of applications such as for use in consumer or commercial goods such as disposable absorbent articles, medical products, and the like. It would be particularly advantageous to provide a fastening system, such as a tab and slot fastener, comprising a structure exhibiting preferential bend. It is desirable that the fastening system be relatively stiff in one direction to aid in application or processing but remain relatively pliant in an opposing direction to improve comfort. It would also be advantageous to provide a structure exhibiting a preferential bend in an absorbent core of an absorbent article to aid in functionality. Furthermore, it would be advantageous to provide a structure exhibiting a preferential bend in a gasketing region of an absorbent article so as to aid in the containment function and comfort of the article.